<!-- Licensed under a BSD license. See license.html for license -->
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
    <title>Three.js - PostProcessing - GUI</title>
    <style>
    html, body {
        height: 100%;
        margin: 0;
    }
    #c {
        width: 100%;
        height: 100%;
        display: block;
    }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
  </body>
<script type="importmap">
{
  "imports": {
    "three": "../../build/three.module.js",
    "three/addons/": "../../examples/jsm/"
  }
}
</script>

<script type="module">
import * as THREE from 'three';
import { EffectComposer } from 'three/addons/postprocessing/EffectComposer.js';
import { RenderPass } from 'three/addons/postprocessing/RenderPass.js';
import { BloomPass } from 'three/addons/postprocessing/BloomPass.js';
import { FilmPass } from 'three/addons/postprocessing/FilmPass.js';
import { OutputPass } from 'three/addons/postprocessing/OutputPass.js';
import { GUI } from 'three/addons/libs/lil-gui.module.min.js';

function main() {

	const canvas = document.querySelector( '#c' );
	const renderer = new THREE.WebGLRenderer( { antialias: true, canvas } );

	const fov = 75;
	const aspect = 2; // the canvas default
	const near = 0.1;
	const far = 5;
	const camera = new THREE.PerspectiveCamera( fov, aspect, near, far );
	camera.position.z = 2;

	const scene = new THREE.Scene();

	{

		const color = 0xFFFFFF;
		const intensity = 6;
		const light = new THREE.DirectionalLight( color, intensity );
		light.position.set( - 1, 2, 4 );
		scene.add( light );

	}

	const boxWidth = 1;
	const boxHeight = 1;
	const boxDepth = 1;
	const geometry = new THREE.BoxGeometry( boxWidth, boxHeight, boxDepth );

	function makeInstance( geometry, color, x ) {

		const material = new THREE.MeshPhongMaterial( { color } );

		const cube = new THREE.Mesh( geometry, material );
		scene.add( cube );

		cube.position.x = x;

		return cube;

	}

	const cubes = [
		makeInstance( geometry, 0x44aa88, 0 ),
		makeInstance( geometry, 0x8844aa, - 2 ),
		makeInstance( geometry, 0xaa8844, 2 ),
	];

	const composer = new EffectComposer( renderer );
	composer.addPass( new RenderPass( scene, camera ) );

	const bloomPass = new BloomPass(
		1, // strength
		25, // kernel size
		4, // sigma ?
		256, // blur render target resolution
	);
	composer.addPass( bloomPass );

	const filmPass = new FilmPass(
		0.5, // intensity
		false, // grayscale
	);
	composer.addPass( filmPass );

	const outputPass = new OutputPass();
	composer.addPass( outputPass );

	function resizeRendererToDisplaySize( renderer ) {

		const canvas = renderer.domElement;
		const width = canvas.clientWidth;
		const height = canvas.clientHeight;
		const needResize = canvas.width !== width || canvas.height !== height;
		if ( needResize ) {

			renderer.setSize( width, height, false );

		}

		return needResize;

	}

	const gui = new GUI();
	{

		const folder = gui.addFolder( 'BloomPass' );
		folder.add( bloomPass.combineUniforms.strength, 'value', 0, 2 ).name( 'strength' );
		folder.open();

	}

	{

		const folder = gui.addFolder( 'FilmPass' );
		folder.add( filmPass.uniforms.grayscale, 'value' ).name( 'grayscale' );
		folder.add( filmPass.uniforms.intensity, 'value', 0, 1 ).name( 'intensity' );
		folder.open();

	}

	let then = 0;
	function render( now ) {

		now *= 0.001; // convert to seconds
		const deltaTime = now - then;
		then = now;

		if ( resizeRendererToDisplaySize( renderer ) ) {

			const canvas = renderer.domElement;
			camera.aspect = canvas.clientWidth / canvas.clientHeight;
			camera.updateProjectionMatrix();
			composer.setSize( canvas.width, canvas.height );

		}

		cubes.forEach( ( cube, ndx ) => {

			const speed = 1 + ndx * .1;
			const rot = now * speed;
			cube.rotation.x = rot;
			cube.rotation.y = rot;

		} );

		composer.render( deltaTime );

		requestAnimationFrame( render );

	}

	requestAnimationFrame( render );

}

main();
</script>
</html>
